Arc-lamp electrode.



G. EGLY. ARG LAMP ELEGTRODB. APPLICATION FILED SEPT. 2s, 1909.

Patented Aug. 27, 1912.

instelt.

,Wirren etentjes indiener menten.

' otono nii-ninos BERLIN, GERMANY, fessilenon 're einen. sinnnns e oo., ons ennuie,

l Gentilini?, e. eozennmnnnsmie.

To all whom zmay concern:

Be it known that l, GEORG Eem?, e snbject of the German Emperor, and residing;l

. et Berlin, Germany, have iiivented certain new and useful lmprovements'in .fiere-llamo Electrodes, `oi' which the. following is :t specification.

My invention relates generally to ero lsmpeleetrodes and poriueularly to those `containing light emitting substances.

As essentiel constituents oi the light emittingsubstinces l use molybdetes ortungstates oi' rare eorths. The molybdates or tungstntes "of reife eerths een be substituted metals which, mixed with tungstio scid or tungstztes oit the elkelis and earth elkalis or other tungstetes, form With the. rare eerths tnngstates or 'molybdetes oi the rare esrths. 4 My invention resides, broadly speaking, in the discovery that the tungstates or their equivalents, the molybdetes, olf the rare eerths ere. unusually valuable liglitgiving ingredients for nre light electrodes. 'These light emitting substances are distinguished by their emitting greet Vlight sind one having* en egreenble color similar to,sunlight.- Now l have also 'found that the light emit-ted con beincreesed when in addition e compound ot iron is added, e. g. tungstste oi iron. A.dmixtures oit iiuorids ere also very edventsgeous.,particularly :duorids oi the rare earths or alkaline eertlis. Suelo iinorids bring about, on the one'bend, e. still greater increase in light when the dnorids are. shitsibly selected, but above ell, they' cesse the light emitting substances to be ve'porlze'd .uniformly and the electrodes to burn quietly.v This is advantageous particularly in those electrodes which nre meent lor 1n closed ere lamps.

An electrode according to my int-ntidii may, for exemple, consist of e shell oipure carbon Containing :i core which is composed ot about %V of e. mixture of molybdetes and tungststes ot the rare eertlis, about 20% tungstste ot iron, end about 20% dnorids ot the rare eorthsor luorspar.

nant, I may use tar, Water-gloss or t `vertieel sectional elevation.l

.la-mp electrodes, a tunfgstete of e rare earth, i

9 nn iron compound, an

Specification oli' Letters Patent. Pgitmtd Aug 2Q', 19H2,

Application filed September Ztl, 1 99. eel-itl4 No519, 986. y

4 K Y m* L M As a lutig like for example.

As an additional example ot theinvention l ,give the following composition, viz.,v30% cerium tungstste, 15% lsnthenium tung,r` stette, 15% didymium tungstate, 10% iron tungstete and 30% fluoispmz As is gen-v erally undeistood, the yeleetrodes are prepared by mixing the ingredients 4together with the addition of as much Water glass as will make "a pasty dough like mass, which is then in the usuel manner filled into the carbo-n shells or tubes. The electrodes so made :ire` then dried in en oven. .It Will be understood, es above sta-ted, that instead ot' water glass ter may be'employed to make the mess plastic. l

ln the accompanying drawing part of en` are lamp electrode `according to invention is represented byvwny of example in ln the drawing@ designates the carbon shell surrounding n core b of the ebovedescribed composition.

'As for the purposes of this speointion` regsrd the molybdetes' of the rare sarthe es, the equivalent of the tungstetes oi' the rari.v eerths, Wlnerel use in the claims the Words' tungstete of rare earth, it is to be understood that this term is used to include also the molybdetes of the rare eartlis for the purpose of avoiding nlternetiveness of. expression.

l elsim: y

l. As s light emitting ingredient of are lamp electrodes, n tungstste of e rare earth.

2. Aslight emitting ingredients of are lamp eleetrodes, substances which yield upon reaction a tungstate or tungstetes of the rare sarthe.

3. As light emitting ingredients of are lamp electrodes, e tungstate of orare earth 'x end an iron compound.

Il. As light emitting ingredient-s. of are 1x00 lomp electrodes, n tungstate of s rareeerth end an iron tungstete.

5. As light emitting ingredients of ure n iiuorid. Y 6. fis light emitting ingredients of ero lamp electrodes., n tungstate of orere earth,

en iron compound, and e iiuorid of o rare earth.

7. As light emitting ingredients ot ere 13b lamp electrodes, a tungstate of rare earth, In testimony Wherof I have signed my and a fluorid. name to this specication in the presence of 8. 'As' iight emitting ingredients of are two'witnesses. lamp electrodes, a mixtre comprising subl(BJORGr EGLY. 5 stantially 60% oi rare earth tun state, 20% Witnesses:

of tungstatepf iron and 20% 0% uqrid of HENRYHASPER,

rare earth. WOLDEMAB HAUPT. 

